Bird Flu Spreads to Humans Easier Than Thought

Until recently bird flu was thought to be transmissible to humans only sporadically. A new study, published in the January 9th issue of the Archives of Internal Medicine, indicates that this may not be true.

The study was done in Vietnam in 2004. Over 45,000 participants were asked screening questions about exposure to poultry and flulike illnesses during the preceding months. Researchers identified a dose-response relationship between poultry exposure and flulike illness. Experts estimated 652 to 750 cases of flulike illness were attributed to direct contact with sick or dead poultry.These findings indicate that avian influenza is more easily transmitted from poultry to humans, although close contact seems required.

The flipside of this story is that the human variant of bird flu is less deadly than previously thought. Until now experts thought the mortality of bird flu was close to 50% among humans affected. This figure is based on the cases of confirmed, mostly hospitalized bird flu victims. What this new study implies is that there may be many more cases of human variant of bird flu in the communities where birds are affected that have milder forms of the disease.

But there is another twist to this story. If the human variant of bird flu is more common among humans than previously thought, that means the chances the virus may mutate and become easier to transmit from person to person are higher, too. Which, in turn, means the danger of a flu pandemic is more real than we feared...

The Avian Flu Doc